Alpha-sulfopolyfluoromonocarboxylic acids and derivatives hydrolyzable thereto



qt-SULFOPOLYFLUOROMONOCARBOXYLIC ACIDS AND DERIVATIVES HYDROLYZABLE THERETO David C. England, Holly Oak, Del assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware No Drawing. Application July 12,- 1956 Serial N- 597,321:

17 Claims. (Cl. 260-481) This invention relates to a new class of polyflu'oroacids and more particularly to a new class of polyfluorosulfocarboxylic acids and derivatives thereof.

Certain mixed carboxylic sulfonic dibasic acids are known, including the short chain sulfoaeetic acids wherein the carboxyl and sulfonic acid groups are linked directly to the same carbon atom. Certain of the monohalosulfoacetic acids are also known, including both the bromo and chloro derivatives. However, these acids are not generally preparable by simple high yield procedures and particularly in the case of the bromo and chloro acids are not as stable as is desired.

This invention has as an object the provision of a. process for the preparation of new dibasic organic acids. A further object is the preparation of new compounds having bactericidal utility. Another object is the preparation of compositions for protecting woolen fabricsagainst attack by larvae of the black carpet beetle. Other objects will appear hereinafter.

These objects are accomplished by the present invention of ot-sulfopolyfluorocarboxylic acids and the func-' tional derivatives thereof hydrolyzable thereto containing one sulfo (SO H) group and one carboxyl (COOH) group, or groups hydrolyzable respectively thereto, each singly linked to the same fluorine-bearing carbon, which carbon is otherwise singly linked to atmost one other fluorine or a polyfluorocarbon radical, saturated aliphatic in character and containing other than carbon and fluorine at most One hydrogen and that on the omega carbon, i. e., omega to said fluorine-bearing carbon, of said radical.

The acids can also be formulated as containing the -SO RCO- moiety wherein R is a divalent geminal polyfluorocarbon radical saturated aliphatic in character and having fluorine on the carbon bearing the two free valences and containing in addition to fluorine and carbon at most one other atom and that hydrogen on car-bon omega to the carbon bearing the free valences. R is preferably a polyfluoroalkylidene radical having on carbon only fluorine and at most one hydrogen and that omega. These new a-sulfopolyfluorocarboxylic acids and derivatives have a hydrogen-free a-carbon atom to which is bonded directly and singly two fluorine atoms, or one fluorine atom and an aliphatically saturated, monovalent polyfluorocarbon radical aliphatic in character, -i. e., acyclic or cycloaliphatic, and containing other than carbon and fluorine at most one hydrogen and that on the omega carbon, i. e., terminal carbon, of said radical, and the carboxylic and sulfonic acid groups or derivatives thereof hydrolyzable thereto.

These new acids and their derivatives can be also formulated with the simple structural formula IJnited States Pate t 0 r Patented Sept. 16, 1953 ICC wherein A represents a carboxyl group and B a sulfo group, or groups respectively hydrolyzable thereto and X represents fluorine or a monovalentperfiuorocarbon or EXAMPLE I Part AWPrepar ti n of 3,3,4,4-tetrttflu,orae2,2-di0x0- 1 ,Z-Oxmhietane A pressure, reactor fabricated from borosilicate glass and fitted with a gas entry tube, a thermocouple Well, and means for shaking was charged-with 212 parts. of freshly distilled, anhydrous liquid sulfur trioxide (which had been condensed at room temperature to prevent any polymerization) and the reactor was thenpressured, while being shaken, to 40 lb ./sq. in. gauge with gaseous tetrafll oroethyl'ene. An exo hermic reaction set in at 'once. The reactor Was packed with ice and thereby cooled to bring the internal temperature below C. Gaseous tetrafluoroethylene was repressur ed as needed to maintain the internal pressure at 4'0 l b .[sq., in. gauge over a period of about one hour, atter which no further absorption of tetrafiuoroethylene wasyobtained. A total of about 265 parts of tetrafiuoroethyl'ene was absorbed. The reactor was then bled to the atmosphere, allowed to warm to room temperature, and the reaction mixture removed and fractionated. There was thus obtained 442 parts (92.8% of theo y) of 2-hydroxytetrafluoroethanesulfonic acid sultone (3,3,4,4-tetrafluoro-2,2-dioxo-1,2- oxathietane) as a clear, colorless liquid boiling at 42 C. at atmospheric pressure. Nuclear magnetic resonance spectra indicated the presence of. no other compound.

Another identical preparation resulted in substantially the same results. The product on analysis exhibited a neutral equivalent of 44.9 and 45.2 (theory for pure 2-hydroxytetrafluoroethanesulfonic acid sultone being 45.0).

Another similar preparation using 16 parts of unredistilled stabilized liquid sulfur trioxide (known commercially as Sulfan B) resulted in the isolation of 19.3 parts (535% of theory) of 2-hydroxytetrafluoroethanesulfonic acid sultone as a clear, colorless liquid boiling at 42 C. and exhibiting a characteristic nuclear magnetic resonance spectrum for the sultone.

Aualysis.Calculated for C F O S: S, 17.8%; F 42.2%; .N. E., 45.0. Found: S, 18.1%, 18.1%; F 41.6%, 40.7%; N. E., 45.5. v

This compound and "the preparation thereof form a part of and are explained more fully in the copending application of Anderson and England, application Serial No. 552,224, filed December 9, 1955.

Part.B .-Preparation of fluorosulfonyldifluoroacetyl fluoride "'flll'fi. -A- vigorous and exothermic reaction occurred at once and the liquid reaction mixture was stirred at room temperature with the temperature of the refluxing vapor slowly decreasing. When the vapor temperature had dropped to 33 C. the reaction mixture was cooled and distilled at atmospheric pressure through a short (16 inch) indented fractionation column. There was thus obtained 136 parts (about 75% of theory) of fluorosulfonyldifiuoroacetyl fluoride as a clear, colorless liquid, boiling at 29 C. at atmospheric pressure.

The rearrangement was graphically confirmed by nuclear magnetic resonance. The spectrum of the sultone consists of two peaks of equal intensity indicating equal amounts of two kinds of fluorine. After rearrangement to fluorosulfonyldifluoroacetyl fluoride, the spectrum shows three peaks in the intensity ratio of 1:122. The two equally intense peaks are shifted to the acid fluoride region of the spectrum and correspond to the fluorine atoms in the -COF and SO F groups. The remaining peak of double intensity corresponds to the fluorine atoms in the CF group.

EXAMPLE II Preparation fluorasuZfonyldiflaoroacetic acid A solution'of 94 parts of fluorosulfonyldifluoroacetyl fluoride in 200 parts of ligroin was chilled to C. and 9.5 parts of water was added to the solution slowly with stirring. An exothermic reaction occurred and the reaction mixture was stirred at the reflux for about 742 hour and then allowed to stand at room temperature. Two layers formed in the reaction mixture and the lower one was drawn ofi and warmed on a steam bath until all noticeable traces of ligroin were gone. There was thus obtained 86 parts (75% of theory) of fluorosultonyldifluoroacetic acid as a clear liquid, boiling at 88-90 C. under a pressure corresponding to mm. of mercury. Nuclear magnetic resonance spectra were consistent with the structure, showing the correct fluorine peaks and proton resonance for one acidic hydrogen.

Analysis-Calculated for C HF O S: S, 18.0%; F, 32.0%; N. E., 59.3. Found: S, 17.3%; F, 30.4%; N. E., 62.8.

Another preparation substantially identical resulted in a 62% yield of fluorosulfonyldifluoroacetic acid, as a clear, colorless liquid boiling at 104-106 C. under a pressure corresponding to 143 mm. of mercury; 12

EXAMPLE III Preparation of sulfodifluoroacetic acid and the barium and calcium salts thereof A solution of 17.8 parts of fluorosulfonyldifluoroacetyl fluoride and 12 parts of sodium hydroxide in 500 parts of water was allowed to stand for 18 hours at room temperature (2325 C.) and then passed through a 4 18.7%; S, 15.8%; N. E., 101.5. Found: F, 18.8%; S, 15.7%; N. E., 101.4.

A solution of 4.06 parts of the above sulfodifluoroacetic acid hydrate in 25 parts of freshly boiled distilled water was added with stirring to a freshly filtered solution of 6.31 parts of barium hydroxide octahydrate in parts of freshly boiled distilled water. A faint cloud formed in the solution and was removed by filtration. The resultant clear filtrate was evaporated to dryness at room temperature and then dried in a vacuum desiccator over P 0 There was thus obtained 6.2 parts (94% of theory) of barium sulfodifluoroacetate monohydrate as a white crystalline solid, readily soluble in water.

Analysis.Calculated for C F O SBa.1H O: 41.7%; S, 9.7%. Found: Ba, 41.0%; S, 9.9%.

In the same fashion using 2.03 parts of the above sulfodifluoroacetic acid hydrate and substituting 1.1 parts of powdered calcium carbonate for the barium hydroxide, there was thus obtained an over 90% yield of calcium sulfodifiuoroacetate trihydrate as a white crystalline solid.

Analysis.Calculated for C F O SCa3I-I O: Ca, 14.9%; H O, 20.2%. Found: Ca, 14.3%; H O, 20.9%.

EXAMPLE IV Preparation of methyl fluorosaZfonyldifluoroacetate To a cooled (10 C.) solution of 36 parts of a 3,3,4,4 tetrafiuoro-2,2-dioxo-1,2-oxathietane in about parts of anhydrous diethyl ether was added with stirring 10.8 parts of sodium methoxide at a rate to maintain gentle reflux. At the end of the addition, the reaction mixture was stirred at room temperature for one hour and allowed to stand for 2.5 days. The precipitated sodium fluoride was removed by filtration. Upon distillation of the filtrate, there was obtained 19 parts (50% of theory) of methyl fluorosulfonyldifluoroacetate as a clear, colorless liquid boiling at 118 C. at atmospheric pressure; 11 1.3500.

Analysis-Calculated for C H F O S: F, 29.7%; S 16.7%. Found: F, 29.8%; S, 16.0%.

EXAMPLEV Preparation of isopropyl fluoroszzlfonyldifluoraacetate A solution of 8 parts of isopropyl alcohol in about 70 parts of anhydrous diethyl ether was added with vigorous stirring dropwise over a period of /2 hour to a cooled solution (10 C.) of 21 parts of fluorosulfonyldifluoroacetyl fluoride in about 70 parts of anhydrous diethyl ether. At the end of the addition, the reaction mixture was warmed for /2 hour at steam bath temperatures and then washed twice with 10% aqueous sodium chloride solution. The ether layer was separated and dried over anhydrous magnesium sulfate. Upon fractional distillation there was obtained 10 parts (47% of theory) of isopropyl fluorosulfonyldifluoroacetate as a clear, colorless liquid boiling at 132134 C. at atmospheric pressure; n 1.3572. The product exhibited nuclear magnetic resonance spectra consistent with the indicated structure-see also Example VI.

In the same fashion, using other alcohols and thiols, other esters and thiolesters of the a-sulfoperfiuorocarboxylic acids of this invention can be prepared. Thus, substituting 2,2,2-trichloroethanol and benzenethiol for the above isopropyl alcohol, there were obtained, respectively, the following products:

To a cooled (ice/water bathfsblutiodbf 26 pains of was allbwe'd to 'stand under anl yglro ls :orrtlitig ri s at room temperature for 24 hours. The reaction mixture was then filtered as rapidly as possible and the filtrate p v fractionatedthrough a precision still. The fraction boiln-octanol in about 75 partsof'petroleum ether was added ing at 3 90 C under a pressure corresponding to dropwise h, ri s i t; P t ra "mourn, 5f assumes "retrained. ratifies "is... i WQFP FEPF-PtBPPH :5 ob a n d. fi p rts. 9f; .fluon s f y d l oa ty thi Parts of Petroleum i resultmg mlxture surfed for cyanate as a yellow liquid boiling at 87 C. under a presone hour at mom tempramrefafter the additipn w 10 ,sure corresponding to l06 mm. :of mercury; n 1.45.67. completed. and-finally l w qe at room m f' Nuclear magnetic resonance spectra showed the absence f (Wermght;v QQ mlfi a l ,of any hydrogen in themolecule and indicated the corwrth 10% aqueous sodium chloride solution and tl ie ora f'figgk 'f flfi fifi "a 'a ff gan-ic layer separated j anhydrous 'AnalysisP-Calculated for C F NO S N, 6.4%; F, nesium sulfate. Upon fractional jdistillation, there was j'5 ;1 6.2%; F, 26.0% obtained 48 parts or crude liquid product boiling at 96 98 C. under pressures corresponding to 6 mm. mercury. EXAMPLE IX Upon a furtherjdistillationthrou'gli aprecision fractionaz r tioncolumn, therewias obtained 43; parts 70% oftlieory) y? Z 09 Z"?? i of n-octyl fiuorosulfonylrlifiuoroafciitate as aclear, :coloran my ujam'y i f'fff f less liquid boiling at 8-88 .C. f1;1nder pressures corre- A sollition of 66 parts of 3,3,4,4-tetrafiuoro-2,2-dioxosponding respectively to 3 and 5' of mercury;' n 'l,2-oxathi'etane i 'so 'pam of'"anhydrous diethyl"ether 1.3957. h I Ti: v was added =dropwise with stirring to"acooled'( l0" C.)

Analysis.Cal'culated, for C H' HF O S: F, 20.3%; S, solution of 58.4 f'g. of n-butylaminein"80"parts ofanhy- 11.7%. Found; F, 19.3%; S, 11.7%. I drousdiethy1 ether. The reactionwas vigorous. "When In the samefashion'using other alcohols, including the addition was completed the react-ion mixture 'was glycols, other esters off the ugsiilfoperfluorocarboxylic filtered afnd the filtrate washedwith aqueous 10% sodiacids of this invention a're prep'ar'ed. The thietanecan um "chloride solution. The ether layerwas separated be added to the alcohol 'asfabovefjor vice versa, although and dried over fanhydrous magnesium sulfate Erom generally better; results are Obtained under'thmformer '30 this b'y'p re'cisionl fractionation, th ere wasbbtairied 22.7 conditions. Other inert, liquid organic reaction rrjredia, part (,l 5% of theory) of N-n-butylfluorosulfonyldifluqrosuch as pentane, hexane, ldioxa'ne, "carbonfiefirach loride' acetaniide "as a clear, colorless liquid boilifig'at 97.0 975 can be used interchangeablxwithj the. petroleum ether. C. .und.er. .a pressure corresponding to 4 mrn..of. mercury; The reaction may also be conducted in the absence of n 1.4076, and 13 parts (10% of theory) of N-n-butyla solvent (see Exampleylll Thus sQhStit ting ethyI- (n-butylsulfamyl)difluorqacetan ide as a crystalline solid n f we l '1 r ie'thano1,dsopro flholfan ,2 ,3 ,3 ,4',4, 5 ',S- melting at 39-42" C(jaindjboiliiig as a clear, colorless foc t'afluorblfi ita f ol jfor, fiefa dve, 1 "there"were Iiqiiidat 1'90 191"'C.'i1'iider"a ressure correspo'ridiiigto obtained, rspectiyelyfthe following 4 mm. of mercury.

'i'r'trs 'PercntAnalysis Product i 121. Yield, B. P. Calc'd Found P r e gg??? 9 l i 51 124125so. 7 r m. Lasso-{5: 2: -.Methylfluorosulfonyldifluoroagetate. 20 115116 O 1.3506 See Example III Isopropyl fiuorosulfonyldifiuoroace- F,25.9 F,;25.'6

tate. 30 133-1300 1.3571 -s,-14.e s, 14.5

N.E.,110 N.E.,113 3;fiiiiiraiiiahifiiifihti i 1-3334 5:8 .2 5:8 6

EXAMPLE VII Analysis..Calculated ,jfor C H F NOgS; F, 24.4%; 'Preparation ofphr zyl flu'rosulfo'nyldifliibi'oate'tate 29 137% Found: 243%; 53%; .A x of4 7 P t l p qli wb ts o ,3. Analysis-Calculated,for C H F N O S: F, 13.3%; te afl -l -d om e .-e was @sfi f d 60,N, 9.8%; s, 11.2%. Found: F, 13.1%; 'N, 9.7%;-s, ice/water bath 'temperatures'until the spontaneous i'eac- 1() 6 7 p I tion ceased and slowly warmed to 25 C. at which tem- I In h Same f hi 'u i oth'er amines" other perature the reaction ix ure Was hel Q h u boxamides, sulfoamides, and amine salts of'the. sulfcdiwith stirring. The resulting reactionmixturewaspurified 'fluqrrqacet'ic acid f this invention -are .prepal.edh The by fractionation arid after a'secon'd-precision distillathietape can be addedto the'amirieor vice ve'rs'a. Other @91 there. .Qb fl 2- PQII Qf QO Y) of inert, liquid organic reaction media,fsuch as p'ent'ane, ph yl fluOT0SU1fI1Y1difiu0rQaceta1e .Sl ghflY ql' hexane, cycl'ohexane, dioxane and anhydrous diethyl ,liq bQiling fi 2 P e Correether can be used interchangeably with the petroleum S Pm g to 30 9 I I- Y; ether. The disubstituted products areobtained when Analysia -calculatedfor (3 11 5304 F, the amine reactant is present in;greate,rf than ,equimolar Found; Z2Q proportions based on the thietane. 2Th ujs, "substituting EXAMPLE 111 .n-pqt ami e. y minc.. anilin misi in f-methy k v aniline, mqrpholine, diphenylan'iine, and 2,5-dimethyl- Preparatzon of fluorosulfonyldzflzroroacetyl thzocyanate piperazihe for: the abovelmbutylamline, there "A mixtureof 20.3 parts of sodium thiocyanate' 'and' tained, respectively, the following-products.

To a solution of 1.2 parts of sodium hydroxide in 100 parts of water, was added 1.2 parts of the anilinium (phenylcarbamoyl)difiuoromethanesulfonate of Example IX. The resultant solution exhibited a pH of 6; sutficient caustic was then added to bring the pH to 8.9. The resultant clear solution was then filtered and the filtrate evaporated on the steam bath under nitrogen. There was thus obtained as a residue'8.1 parts (99% of theory) of sodium (phenylcarbamoyl)difluoromethanesulfonate as a white crystalline solid.

Analysis.-Calculated for C H F NO SNa: N, 5.1%. Found: N, 4.8%.

EXAMPLE XI Preparation of fluorosulfonyldifluorothiolacetic acid A pressure reactor was flushed with nitrogen and charged with 36 parts of 3,3,4,4-tetrafiuoro-2,2-dioxo-l,2- oxathietane, flushed again with nitrogen, sealed and pressured to 1000 atmospheres with gaseous hydrogen sulfide. The reactor was maintained under these conditions at room temperature with shaking for several hours and then opened slowly with the gaseous products being bled to atmospheric pressure through a scrubber containing petroleum ether. The lower layer of the resultant petroleum ether mixture was removed and upon distillation there was obtained eight parts of crude fluorosulfonyldifluorothiolacetic acid (21% of theory) as a clear, watersoluble liquid boiling at S7-65 C. under a pressure corresponding to 8 mm. of mercury and exhibiting an odor typical of sulfur compounds, particularly those containing a thiol group.

Analysis.Calculated for C HF O S N. E., 64.7. Found: N. E., 71.4.

Nuclear magnetic resonance spectra showed fluorine resonance characteristic of the fluorosulfonyldifiuoromethyl group and proton resonance with a single peak intermediate in position to the proton resonance peak for AMIDES AND AMINE SALTS Percent Analysis Product Yield, B. P. no

percent Calcd Found F, 19.7 19.0 N-n-Octylfluorosulfonyldifiuoroacetamide-- 27 163-164 O./mm. 1.4237 g1, 13.9 .9 v v F. 9.6 8.3 N-n-Oetyl(n-octylsulfamyl)difluoroacetamidm. 250-270 G./20mm 1.4561 151, 7.;

1 8. F, 24.5 24.0 N,N-Diethy1fluorosulfonyldifluoroacetamide" 63 120-121o. 20 1.4092 5 3-;

, M. P. Crystals F, 22.5 22.9 N-Phenylfluorosulfonyldlfluoroacetamide 98 HIT-108C White 51, 5.2 5.2 12. 12. A 111m 11 1 b l)difi a1 2 5i 11 um enycar amo uoromeanesuuomte? Y 84 BIS-219C So1.h0twater S" m A d in h 1 b 1 4i 9 nisi inium p-me oxyp any car amoy .O Ndgmfi groinet-halnesullgongte. m h 1 i l 33 201 203C 40?2 3 713 pet oxyp any p-me oxyp any sufamyhdifiuoroaeetamide. 25 177 C water 3g 3 3g 5 (IN-Methyl, N-phenyl)fluorosulfenyldifiuoro- N, 522 5:4 acetamide. 69 s, 12.0 12.0

Fluorosulfonyldifluoroaeetylmorpholine [1. e., a 2

fluorosnllonyldifluoroaeetic acid morpholide] 72 C 2:3 F, 17.3 15.7 N,N'-Diphenylfluorosulfonyldlfluoroacetamide. 75-76 0 g1,

F 26.3 26.4 1 4 -B1s (fluorosullonyldifluoroaeetyl) -2,5-d1- methylpiperazine. 64 212 214 White g 1 o EXAMPLE X acetic and .thiolacetic acid and thus consistent with a Preparation of sodium (phenylcarbamoyl) difluoromeththlolqcarboxynlethyl group that a thlqlocarboxy group anesulfonate polarized by linkage to an ad acent dlfiuoromethylene group.

EXAMPLE XII Preparation of fluorasulfonyldifluoroacerhylurea (fluorosulfonyldifluoroacetic acid ureide) A solution of 72 parts of 3,3,4,4-tetrafluoro-2,2-dioxo- 1,2-oxathietane in about 175 parts of petroleum ether was added dropwise with stirring to a cooled 10 C.) suspension of 24 parts of urea in about 150 parts of petroleum ether. The reaction was vigorous and when the addition was completed the reaction mixture was stirred over a period of three hours while the temperature was allowed to rise to 25 C. After standing overnight, the reaction mixture was filtered and after drying there was thus obtained parts of crude fiuorosulfonyldifiuoroacetylurea as a white powder melting at ]44147 C. After one recrystallization from methanol and an ether wash, the solid white crystals obtained from the diethyl ether washings on evaporation were fluorosulfonyldifluoroacetylurea, i. e., fiuorosulfonyldifluoroacetic acid ureide, melting at 152 C.

- Analysis.Calculated for C H F O N S: F, 25.8%; N, 12.7%; S, 14.5%. Found: F, 23.6%; N, 12.9%; S,

EXAMPLE XIII Part A.-Preparalion of 3-trifluoromethyl-3,4,4-trifluoro 2,2-dioxo-L2-oxathietane .trifluoroethanesulfonio acid sultone' 3-trifiuoromethy1- 9 3,4,4-triflt1oro-2,2 dioxo-l,2 oxatliietane) as a clear, color- :Alessliquid boiling -at"46.5 C. at atmospheric pressure.

'-As further characterization the liquid productexhibited a' nuclear magnetic resonance" spectrum consistent with -the -fou'r-me'rnb'ered sultone structure. This compound -and thepreparationthereofform a part of and are ex- *plain'edmore'fully in the copending a jpli ':ation'of "Anders'onandEngland,-'application Serial No. 552,224, filed *De'cember' 9, 1955.

fonyl (trifluoromethyl) fluoroacetamide A solu'tion -of 23.0 parts of 3'-trifiuoromethyl-3,4,4-trifitidroJJ-dioxo-1,2-oxathietane irr about 80 parts of'anhy'drousdietliyl-"ethenwas cooled in' an ice/waterbath -f anda solution of 21.4 parts of N-m'ethyla'nilineinabout 80 pa'rts of anhydrous 'diethyl ether was added"dr'6pwise- 2 wi th vigorous stirring over aperiod of about one half =hour. When the addition was completed, the reaction -'n'lix'turewas stirred for an additional hour andthen allowed to stand overnight to come to'roomtempe'rat-ure. The i reaction 'rnixture was then filtered 'and'the filtratewashed *twicewith aqueous 10% sodium chloride solution. The ether layer was separated and dried over anhydrous magnesium sulfate. After filtration and removal of the "diethyl ether by distillation, there was obtained upon precision fractionation about 5.5 parts of recovered N- methylaniline and 19.7 parts (62% of theory) of (N- methyl N-phenyl)fluorosulforiyl(trifluoromethyDfluoro- ""acetamide' as a clear, colorlessliquid boiling at 108-110 C .;under a pressure corresponding'to 2 mm. of mercury; 1715 1.4598. g I

'Ai1alysis.+Calculated for C HgF OgNS: N; 4.4%;F, "36.0%. Found: N, 5.0%; F, 29.2%. Y

EXAMPLE XIV Preparation of 2-erhylhexyl fluorosulfon'yl(trifludro "m'ethyl) fluoroacetate A'solution of 14.0 parts of 2-ethylhexanol in about 85 upartswfpetroleumether was addeddropwise with vigor- --ous -stirring to a cooled (ice/water bath) solution of --23-.0 parts of 3-tritluorornethyl-3,4,4-trifluoro-2,2-dioxo- -.-1,2-oxat hietane (see-Example XIII, Part A) in about v85 eparts ofpetroleum etherover a period of about one-half -hou'r. Whenthe addition was completed, the reaction mixture-wasstirred for about two hours to warm to 'room =-temperature and-then let stand an additional two hours.

-Thereaction mixture-was then washed twice Withaqueous l;%"sodium Chloride solution and twice with water. The vpetroleurn ether layer-wasseparated and dried over-anhydrous magnesium sulfate. After filtration and removal '--of the petroleum ether-solvent -by distillation, "there was *obthindbyprebision fractionation 20.7 parts (63% 'of theory) of 2-e'thylhexyl"fiuorosulfonyl-(trifluoromethyl) '-'fiuoroacetate as aclear, colorless liquid boilingat 92-94 under apressure corresponding to S'HIHL'Of mercury; "12 113855.

*Analysis."-Calculated-for C H' F O Sr S, 9.8%; F, 26.9%. -Found:"-S,'9'.4%; F, 26.9%.

The present invention has "been illustrated above with 'con'siderable emphasis on the preparation'of sulfodifiiioroa'cetic'acid a'nd a multitude of derivatives thereof which are hydrolyzable'to said acid and the illustration has been e'xtended' to the' acid with the next-higher perfluoroalkylidene radical-since these are most conveniently avail- -ableand fully illustrate the invention. The inventionis, however, generic to ci-sulfopolyfluorocarboxylic acids, i. e., to perfiuorosulfoacetic and a-polyfluorocarbon-substituted *a fluorosulfoacetic"acids in which the polyfluorocarbon group contains -'only' fluorine and at the most onehydro- -;'-gen and that in the omegaposi-tion, and derivatives thereof hydldlyzable thf to, 5' Particularly iiiit' 's taiidiilg hectills f th l'eadier availaliility of the"nece'ssary iiitftheditites l' 's "ids hndfleriva tives thereof hydrolyzahle 'th re- A containing no rnore 'th'an elev'en chain "carbons, e., the gle 'carbon -linki ng the carboxylic andfs ulf onic "groupsfor"derivatives thereof hydrolyzable thereto, plus a' psrfiuero c'arubnwr omega-monohydroperifluorocarhon ic'al of no tnore than ten carbons pendant orr'said uar 10 -As' illustrated in the foregoing eXamp lesfthe erii/atives of the sulfonica nd 'carboxylic acid'groups hy ble theretdinc'ludez 'the' respective acyl' fiuo des i "fidesjetcj rndhoand polyvalent salts "of either *ac'id gro'u'psg including the salts 'of' any" metallic elefrnent,

and particularly the salts of the alkali "forming metals, tie,

the alkali metal and alkaline earth metal salts, as well as the ammonium and' amine salts; the esters of one or both acid groups, including the thiol esters; nitriles; the amides, including both primary, secondary and tertiary airi-idesQofoneorboth acid groups, or the: like. Gen- 'erally-speaking, any substituent radical present in these groups hydrolyzable to the respective acidlgroups usually 'is of ho more than 18-c a rbons, is free of Ze rewitinoffiao tive hydrogen, and preferably contains no more than-eight carbons, free-of active, i. e., reactive, hydrog en. The 'most preferred compounds are the a-sultoperfiuoroal- 'kanoic acids of no more than three carbons with the said acid-groups or groups hydrolyzable thereto containfing only substituents-of no more than eight carbons each free of aliphatic unsaturation and Zerewitinofl? active hydrogen. The new class of compounds of this invention are defined 'chemically by the following simple structural formula: .35

,.F 'AOB X irfwh'ichX is lluorine or" the group (CF MY'wHiein'Y is flt'roi'ineor hydrogen and n is awholeintegertftbm I to 10, inclusive, A represents a carboxyl groupand B -a guuoegrau or groups hydroly za ble respectively thereto, including, for instance, the acid halides, e. g. ,the acidfluorides; the thiolo acids, the amides, "incl uding 'monoand di 'substituted amides; the esters and thiolo esters; the ammonium, substituted ammonium and metal salts; nitriles and the like, wherein any substituentsin said 'aci d precursor-groups are alike or diiferent and: are generally wholly hydrocarbon free of aliphatic unsaturation and Zerewitinoff activehydrogen and preferably o f no more than 18 carbons and the metals'are those ofgroups *IaVIIIjof the periodic table' and preferably the alkali and alkaline earth metals. The radical prefer ably perfiuoro carhon, and desirably alindroalkylidene. -In thepreferredcompounds X is fluorine or perfiuorornthyl and A and B are used to indicate the just-described groups hydrolyzable respectively to -C OH :and 50 1-1 wherein any radical substituents R are monovalentorganic-radicals free of ZereWitinofi' actiye hydro- -;gen and of nomore thancight' c'arbonseach. I The most preferred compounds have any radical substituents-R as raboveand also free of aliphatic unsaturation, i. e., nonaromatic' unsaturation. p

-The new-compounds of the present invention may conveniently be made employing as the raw materials the cyclic sultones of the corresponding '3,4,4-trifluoro- 2',2- dioxo-1-,2-th-ietanes carrying in the 3 position fluorine, 7 aperfluorocarbon, or omega-hydroperfiuorocarbon radicals which-can bemadeby the process of the copendingapplication of; Anderson and England, Serial No. 552,224, -filed--December 9, 1955, and whose preparation and prop- -';ertiesT-are more fullyexplained therein. For the preparation of the sultone intermediates of the present invention a polyfluoroolefin having one and only one aliphatic unsaturation and that a terminal double bond, and other than carbon and fluorine at most one hydrogen and that in the omega position to the double bond, preferably having fluorine on each doubly bonded carbon, is reacted with freshly distilled, anhydrous sulfur trioxide under pressure if desired and with maintenance of moderate temperature, e. g., below 100 C. While any polyfluoro terminally unsaturated monoolefin can be employed the polyfluoro-l-alkenes are preferred and of these the polyfluoroalkenes of up to twelve carbons are particularly preferred because of greater availability, etc. The reaction mixture is fractionally distilled to separate the sultone from unreacted materials, etc. These sultones have the structural formula:

X-SO2 1 20-4 wherein X is fluorine or a monovalent perfluorocarbon or omega-hydroperfluorocarbon radical free of aliphatic unsaturation and of no more than ten carbons. The preferred sultones are those of the u-hydroxyperfluoroalkanesulfonic acids of up to three carbon atoms.

These sultones, as illustrated by the examples, can be used frequently as an intermediate for direct interaction with, for instance, an alcohol or an amine, or ammonia, to form the new esters and amides of the aforesaid described a-sulfopolyfluorocarboxylic acids. Alternatively, these sultones can be rearranged first under basic conditions, as shown in Example I, to form the diacid fluorides of the respective a-fluorosulfonylpolyfluorocarboxylic acids (which in themselves form a part of this new class since they are hydrolyzable to the corresponding dibasic acids) with the said diacid fluoride being later reacted with the other necessary intermediate to form the required derivative, e. g., with an alcohol, mercaptan, ammonia, hydrazine, or an amine or a metal hydroxide to form the corresponding esters, thioesters, amides, hydrazides, or salts of the u-sulfopolyfluorocarboxylic acids. For reasons as yet unknown, the rearrangement step has proven to be essential in the formation of the thiolo acids.

The acids of this invention and their salts, esters, and amides can be interconverted. Thus any of the a-fluorosulfonylpolyfluorocarboxylic acids or a-sulfopolyfluorocarboxylic acids of this invention can be directly converted to the bis-ammonium salt by a simple metathetical reaction with ammonium hydroxide. Polyvalent metal salts, e. g., those of copper, lead, nickel, cadmium, iron, zinc, tin, mercury, etc., can be made from the oxide or carbonate of the metal and an aqueous solution of the Ot-SlllfO- polyfluorocarboxylic acid. In the case of the alkali metals, the monoor bis-salts can be achieved. However,

in the case of the polyvalent metal ions, because of the high degree of stability afforded by the thereby achieved six-membered ring structure, only the mono salts are normally attained with both the carboxylic and sulfonic acid groups ionically salt linked to a single polyvalent metal ion.

The sulfonic acid esters are conveniently prepared by metathesis of the ct-fluorosulfonylpolyfluorocarboxylic acids with a metal (e. g., a monovalent alkali metal) alcoholate of the desired alcohol, e. g., sodium methoxide, sodium phenolate, etc., followed by acidification of the resulting sodium carboxylate of the methyl or phenyl sulfonate. The carboxylic/sulfonic bis-esters are prepared from the fluorosulfonylpolyfluorocarboxylic acid esters by formation of the sodiosulfonyl salt and subsequent reaction with an ester, preferably an inorganic acid ester, e. g., a hydrohalic acid ester, of the desired alcohol. The a-sulfamyl and substituted sulfamylcarboxylic acids are prepared from the u-fluorosulfonylpolyfluorocarboxylic acids by heating first with ammonia or the necessary amine having hydrogen on nitrogen, e. g., diethylamine, cyclohexylamine, morpholine, piperidine, hexamethylenediamine, etc., and subsequent acidification.

' The u-carbamoyl and substituted carbamoylpolyfluorosulfonates are prepared from the corresponding carbamoyl and substituted carbamoylpolyfluorosulfonyl fluorides and by alcoholysis of the sulfonyl fluoride directly with a metal alcoholate of the desired alcohol. The hydrazides and substituted hydrazides of either or both the sulfonic or carboxylic acid groups are prepared in the manner above illustrated for the carboxylic acid amides and the sulfonic acid amides. Many other variations are possible in the many routes available for synthesis of the new derivatives of the a-sulfopolyfluorocarboxylic acid hydrolyzable to the said acids, these methods and the variations possible therein being well known to the skilled chemist.

By the methods above indicated there are prepared, in addition to the numerous derivatives prepared in the examples: the eleven carbon main chain wfluorosulfonylperfluorocarboxylic acid fluoride, a-fluorosulfonylperfluorododecanoyl fluoride from 3-perfluorodecyl-3,4,4-trifluoro-2,2-dioxo-1,2-oxathietane by base catalyzed rearrangement as in Example I from which diacid fluoride the various salts, amides, esters, hydrazides are prepared as above; a polyvalent alkaline earth monometal salt of an a-sulfo nine-carbon main chain perfluorocarboxylic acid, i. e., barium a-sulfonatoperfluorodecanoate from 3-perfluorooctyl-3,4,4-trifluoro 2,2 dioxo-l,2-oxathietane by base catalyzed rearrangement, as in Example I, to the diacid fluoride and salt-forming metathesis with barium hydroxide; a seven carbon main chain hydrocarbon fluorosulfonylperfluorocarboxylate, e. g., n-propyl a-fluorosulfonylperfluorooctanoate from 3-perfluorohexyl-3,4,4-trifluoro-2,2-dioxo-1,2-oxathietane by reaction with sodium n-propoxide; and N,N'-bis branch chain eight carbon hydrocarbon sulfamyl six-carbon chain perfluorocarboxamide, e. g., N-Z-ethylhexyl(2-ethylhexylsulfamy1)perfluoroheptanoamide from 3-perfluoropentyl-3,4,4-trifluoro- 2,2-dioxo-1,2-oxathietane by reaction with two molar proportions of Z-ethylhexylamine; a cycloalkyl a-fluorosulfonyl four-carbon main chain perfluorocarboxylic acid ester, e. g., cyclohexyl a-fluorosulfonylperfluorovalerate from 3-perfluoropropyl-3,4,4-trifluoro-2,2-dioxo-l,2-oxathietane and cyclohexanol; a dihydrocarbon ester of an a-sulfoperfluorocarboxylic acid, e. g., dodecyl iii-(methylsulfonato)perfluoropropionate from 3-perfluoromethyl- 3,4,4-trifluoro-2,2-dioxo-1,2-oxathietane by reaction with dodecyl alcohol to form the dodecyl a-fluorosulfonylperfluoropropionate and metathesis thereof with sodium methylate to form the methyl sulfonic acid ester; an eighteen carbon hydrocarbon carboxylate of an a-fluorosulfonylperfluorocarboxylic acid, e. g., octadecyl a-fluorosulfonylperfluoroacetate from 3,3,4,4-tetrafluoro-2,2-dioxo-l,2-oxathietane and octadecyl alcohol; an aliphatically unsaturated hydrocarbon a-fluorosulfonylperfluorocarboxylate, e. g., decenyl u-fluorosulfonylperfluoroacetate from 3,3,4,4-tetrafluoro-2,2-dioxo-1,2-oxathietane and decenyl alcohol; etc.

By the methods for the examples given above, 3- (omega-hydroperfluorohexyl)-3,4,4-trifluoro 2,2 dioxo- 1,2-oxathietane is reacted with a small amount of triethylamine to obtain a-fluorosulfonyl-omega-hydroperfluorooctanoyl fluoride. This acid difluoride is reacted with methyl alcohol to yield methyl a-fluorosulfonylomega-hydroperfluorooctanoate. Reaction of the acid difluoride with dibntylamine yields N-dibutyl oz-flUDIOSUlfonyl-omega-hydroperfluorooctanoamide.

The six carbon main chain a-fluorosulfonyl-omegahydroperfiuorohexanoyl fluoride is prepared by reacting 3-(omega-hydroperfluorobutyl) 3,4,4 trifluoro-2,2-dioxo-l,2-oxathietane with a small quantity of triethylamine. Treatment of the acid difluoride with water followed by reaction with sodium hydroxide and with barium hydroxide yields sodium and barium a-sulfonatoomega-hydroperfluorohexanoates, respectively.

N-diethyl a-fluorosulfonyl-omega-hydroperfluorododecanoamide is prepared by adding diethylamine gradually to a solution of 3-(omega-hydroperfluorodecyl)-3,4,4-tri- 13 flUOIO-ZfidlOXO-1,2-Xfilhl6l3ll6Ill petroleum ether. This thietane is also reacted in the same manner with N-rnethylaniline to yield N-methylphenyl-u-fluorosulfonyl-omegahydroperfluorododecanoamide.

The acid chloride, a-fluorosulfonyldifluoroacetyl chlo- 'ride, is prepared by reacting oe-fiuorosulfonyldifluoroacetic 1 acidwith thionyl chloride and-distilling the acid chloride from the reaction mixture. The diacid chloride, tit-chlorosulfonyldifluoroacetyl chloride, is-preparedby reacting a-sulfodifluoroacetic acid with phosphoruvpentachloride and distilling the diacid chloride fromthe reaction mixture.

The new compounds ofthis invention, i." e., u-sulfopolyfluorocarboxylic acids and derivatives thereof hydrolyzable thereto are generically useful as-bactericides, i. e., in decreasing and most desirably in preventing the growth of bacteria. Thus, the (N-methyl-N-phenyl)fluorosulfonyldifiuoroacetamide of Example 1X, when added in concentrations as low as 10 parts per million inhibits the growth of the bacterium Clostridium pasteurianum in a 2% aqueous sucrose solution containing added inorganic saltssaid medium being described by Jensen et a1.,

; Linnean .Soc., NewaSouth Wales, .72, 73 (1947.).

:Tihe following detailed test data .show. this bactericidal .sfeifect ,against conventionaltest bacteria for they ethylene :1 bis(fluorosulfonyldifluoroacetate) of Example YLxthe phenyl' fluorosulfonyldifluorothioloacetate ofztExample v, standtthe-fluorosulfonyldifluoroacetyl urea of Example X11, tzinzspecifieillustration of this genericutility 'ofpthisxnew xielass of compounds.

The test bacteria were grown in 2% tryptose broth for 18-24: hours at 37 C. The test organism was then inoculated into melted 2% tryptose agar and this poured into vsterile Petri plates and allowed to harden. One-half inch diameter paper disks .of sterilefilter' paperirnpregnated with the compound under test were then placed on the surface of the inoculated agar plates and the plates incubated at 37 C. for 18-24 hours. Impregnation was carried out by treatment of the disks individually with 0.1 ml. of a solution of 50 mg. of the test compound in 5 ml. of acetone, followed by evaporation of the acetone-all at room temperature. The final concentration of compound per dry, treated disk, was 1000 micrograms (1000 ,ug.).

The width of the zone of inhibition of bacterial growth surrounding the paper disk was measured. This zone corresponds to the absence of all growth of the test organism and is indicative of the potency of the compound tested. In the absence of the additive there is no such zone, i. e., the organism grows in all areas. In Table I, the zones of inhibition (in mm.) are shown for the following compounds:

A=ethylene bis (fluorosulfonyldifiuoroacetate) B=phenyl fluorosulfonyldifluorothioloacetate C=fluorosulfonyldifiuoroacetyl urea TABLE I.ZONES OF INHIBITION (IN MM.), AGAR PLATE TEST Micrococcus Strepto- Escherichia Pseudopyogenea coccus 60h, Strain monas aeru- Compound var. aureus, faecalis, 6A uinosa,

H Strain 1001 Temple Strain "---the former) to samples "of -wool'en' fabric in 'amounts --'su'ch---as to give from 055.0%" of the compound based on "the fabric, at-which concentrations "substantially no 5 fabric damage or change in fabric properties occursjdamage from the black carpet beetle larvae 'is I substantially completely prevented. Thus, the fluorosulfonyldifluoroacetyl fluoride of Example I was dissolved in methylene chloride -at -a' concentration "of 10%= and 'swa'tches of 10-sirigle=weight wool blanket-fabriewere immersed-in said solution, for onehour at 25C., removed, dried,washed briefly in cold-water and dried' again. The treated sample contained 0.82% fluorine" by analysis- (correspond- -ing to' about 1.95%, bywei'ght'of'the fabric, "of theacid "flu0ride). "The treated sample was' then exposed to la'r vae of the black carpet beetle for 21 'days, at the' 'endof which time the treated wool-sample: exhibited no real fabric' damage (shearing ofsurface fibersf-onlyy F: In contrast, a control (tuntreated)"wool-- blanket fa'br ic samzo 'pley exposed "at the sametime and under the-same conditions for'the same length of time, showed 15%fabric damage. 1-Eurtherrrrore, in the testwith the treated-fabric sample, there was obtained 71mg; frass in contrast to the.':'13-.8*mg; obtainedinithe duplicate testswithithe con- 25 trol, i. e.,:untreated fabric. sample. The term *frass refers tottheweight of fecal'mater-ialpassed by a No. 4 I 'Gootch cru'cibIeand-is an indirectmeasure of the' wool consumed :by the: insects.

The new a-sulfopolyfluorocarboxylic acids and deriva- .tivestthereofhydrolyzable thereto of this invention are also usefulfor conversion thereto to the carboxylic acid :.halides. These areuseful as agents or intermediates for .improving the .dyea bility of fibers and fabrics, more .particularly of fibers andfabrics prepared from synthetic polymers where adequateand especially good'd'yeability is frequently achieved only with extreme difficulty. Thus, when a fabric woven from fibers of polyethylene terephthalate was immersed in a petroleum ether solution of the a-fiuorosulfonylperfluoroacetyl fluoride of this invention, dried and dyed with basic dyes, the treated sample showed a noticeable improvement, i. e., was more deeply colored, over a control sample of the untreated fabric dyed under identical conditions. The other derivatives of this invention can be converted to the acid chloride by conversion to the free acid and thence to the acid chloride (via thionyl chloride). The acid chlorides are substantially as effective as the acid fluoride.

The new products of this invention, because of their diacid functionality, are useful in the preparation of condensation polymers, including both polyesters and polyamides by reaction with the well-known classes of diand higher functional glycols and diamines. More particularly, when the ethylene bi-s-(a-fluorosulfonylperfluoroacetate) of Example VIwas reacted under polyesterforming conditions with hexamethylene glycol (see U. S. 2,071,250, -251, -253), there was obtained a soft, watersoluble, polyhexamethylene glycolethylene glycol mixed ester of perfluorosulfoacetic acid. The polymer on drawing while moist with water formed fibers. These water soluble fibers can be used in a multitude of uses now known for water soluble fibers. A relatively brittle, yellow, solid resin was obtained by reacting the sultone precursor of fluorosulfonylperfiuoroacetyl fluoride, i. e., 3,3,4,4-tetrafluoro-2,2-dioxo-1,2-oxathietane, with a mixture of the three geometric isomers of bis(p-aminocyclohexyl)methane under polyamide-forming conditions (see above patents). This poly-bis(p-aminocyclohexyl)methane/perfiuorosulfoacetic acid amide melted at 151-155 C., was soluble in acetone and dimethyl formamide, and

7 upon analysis was shown to have a molecular weight of about 1100 corresponding to three units of the polyamide-forming ingredients, i. e., the diamine and the dibasic acid. The amine can be employed to impregnate and stiffen paper and cloth.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described for obvious modifications will occur to those skilled in the art.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

I claim:

1. A member of the class consisting of saturated a-sulfopolyfluoromonocarboxylic acids and derivatives thereof hydrolyzable thereto, said acids having the sulfo group, the carboxyl group and at least one fluorine attached to the terminal carbon of a saturated polyfiuorm carbon radical, and having, in addition to fluorine and carbon in said radical, at most one other atom and that hydrogen on the omega carbon.

2. A saturated a-sulfopolyfluoromonocarboxylic acid having the sulfo group, the carboxyl group and at least one fluorine attached to the terminal carbon of a saturated polyfluorocarbon radical, and having, in addition to fluorine and carbon in said radical, at most one other atom and that hydrogen on the omega carbon.

3. An ester of an acid according to claim 2.

4. An acid halide of an acid according to claim 2.

5. An amide of an acid according to claim .2.

6. A saturated a-sulfopolyfluoroalkanoic acid having the sulfo sulfur and carboxyl carbon joined by a divalent polyfiuoroalkylidene radical having fluorine on the one carbon bearing the free valences and having in addition to fluorine and carbon in said radical at most one other atom and that hydrogen on omega carbon.

7. A saturated a-sulfoperfluoromonocarboxylic acid having the sulfo sulfur and carboxyl carbon joined by a geminal divalent saturated perfluorocarbon' radical, and

having fluorine on the one carbon bearing both free valences.

8. A saturated u-sulfoperfluoroalkanoic acid having sulfo sulfur and carboxyl carbon joined by a perfluoroalkylidene radical.

9. A saturated a-sulfoperfluoroalkanoic acid having sulfo sulfur and carboxyl carbon joined by a perfluoroalkylidene radical of up to twelve carbons.

10. Sulfodifiuoroacetic acid.

. An acid halide of sulfodifluoroacetic acid.

. An ester of sulfodifluoroacetic acid.

. An alkyl ester of sulfodifluoroacetic acid.

. A lower alkyl ester of sulfdifluoroacetic acid. An amide of sulfodifluoroacetic acid.

. Fluorosulfonyldifluoroacetyl fluoride.

. A compound of the formula:

wherein (1) the groups on the carbon atom are joined only through said atom; (2) X is a member of the class consisting of fluorine and the group (CF ),,Y, n being an integer from 1 to 10 and Y being a member of the class consisting of fluorine and hydrogen; (3) A is a member of the class consisting of carboxyl and groups hydrolyzable thereto; and (4) B is a member of the class consisting of suite and groups hydrolyzable thereto.

References Cited in the file of this patent FOREIGN PATENTS 662,572 Great Britain Dec. 5, 1951 

1. A MEMBER OF THE CLASS CONSISTING OF SATURATED A-SULFOPOLYFLUOROMONOCARBOXYLIC ACIDS AND DERIVATIVES THEREOF HYDROLYZABLE THERETO, SAID ACIDS HAVING THE SULFO GROUPS, THE CARBOXYL GROUP AND AT LEAST ONE FLUORINE ATTACHED TO THE TERMINAL CARBON OF A SATURATED POLYFLUOROCARBON RADICAL, AND HAVING, IN ADDITION TO FLUORINE AND CARBON IN SAID RADICAL, AT MOST ONE OTHER ATOM AND THAT HYDROGEN ON THE OMEGA CARBON. 